Draught (or draft) beer or malt based fermented beverages (collectively referred to herein as “beer”) is often preferred by consumers to bottled or canned beer. Draught beer is generally served at the counter of a public house or restaurant out of a refrigerated keg. The keg is connected to a source of pressurized gas in order to increase the pressure inside the keg and thus drive the dispensing of the beer through a dispensing tube fluidly connecting the keg to a dispensing tap, comprising a valve for controlling the flow out of said tap.
Draught beer was—and still widely is—traditionally stored in large capacity re-usable metal kegs, typically 50 l kegs (=11 Imperial gallons). Once the kegs are empty, they are returned to the brewer for cleaning and filled with new beer. In recent years, however; a reduction of the kegs capacity offered on the market has been observed. There are two main factors explaining this trend.
First, brewers have developed various solutions for offering draught beer to individuals with specifically designed home appliances. It is clear that if 50 l kegs can be emptied reasonably rapidly in a public house (=pub) or a restaurant, this is not the case for home appliances. Hence, smaller kegs of the order of 2, 3.5, 6, or 12 litre capacity were developed. Such home appliances are often referred to as “table top dispensers” because they are small enough to stand on top of a table.
Second, even in pubs, the tastes of the consumers have shifted from traditional lager beers towards special beers, with more specific flavours. This diversification of the types of beers offered for consumption in pubs has pushed brewers to store their special beers in smaller capacity kegs, ranging from 10 to 25 l kegs. Since such kegs are too large to stand on top of a counter, and probably too small to justify storing them in a basement far away from the tap, they are usually stored directly under the tapping column, usually in a refrigerated chamber or closet. For this reason and by opposition to the expression “table top dispensers”, such dispensing systems used in pubs are often referred to as “under the counter dispensers”.
With smaller kegs, collecting, cleaning, sterilizing, re-filling and re-distributing metal kegs becomes too expensive and has a substantial ecological impact. For this reason, containers (or kegs) made of polymer, e.g., in polyester such as PET, have been developed which are totally recyclable, thus considerably reducing the ecological impact and cost of packaging draught beer. Particular examples of polymeric kegs are so-called bag-in-containers, wherein the keg comprises an outer container which is relatively rigid and mechanically stable, and an inner bag, which is flexible and contains the beer to be dispensed (cf. FIG. 2). Dispensing of the beer out of a bag-in-container is driven by injecting pressurized gas between the outer container and the inner bag, thus squeezing the latter and expelling the content of the inner bag out into a dispensing tube. One major advantage of bag-in-containers is that the pressurizing gas does not contact the liquid to be dispensed, and a simple compressor or pump can be used, instead of the traditional CO2 pressure bottles. Examples of polymeric bag-in-containers can be found in EP2146832, EP2148770, EP2148771, EP2152494.
As is often the case in fields having a well established tradition, this change of keg format and materials is, at least in a first stage, implemented by simple replacement of the large metal keg by polymeric kegs, generally smaller in size, without changing any of the other auxiliary elements of the dispensing appliances, such as keg connectors, tubing, storing closet for storing the kegs, etc. New keg connectors and storing closets particularly suitable for polymeric kegs of smaller format have been recently proposed in European patent applications No EP14181401 and EP14161266.
Collecting metal kegs in a cycle of cleaning and re-using them has quite different demands than collecting polymeric kegs for recycling of the polymeric material. For example, the polymeric kegs are advantageously squeezed prior to transportation so as to reduce the volume of empty kegs, when this is of course out of question with metal kegs meant to be re-used. It is therefore problematic to squeeze an empty container which interior is pressurized, as more energy is required to overcome the inner pressure, and when the inner pressure is released it can be unpleasant, if not dangerous, as it can be accompanied by a sudden burst.
It can be seen from this review of the prior art, that it remains a need in the art for a dispensing appliance which is better adapted for use with the new generation of smaller, polymeric kegs, which are meant for recycling instead of re-using. This and other objects of this invention will be evident when viewed in light of the drawings, detailed description, and appended claims.